The present invention presents a silica particle containing at least one silica compound selected from a group consisting of mercapto-propyl-trimethoxysilane (MPS), mercapto-propyl-triethoxysilane (MPES), mercapto-propyl-methyldimethoxysilane (MPDMS), trimethoxy[2-(7-oxabicyclo[4.1.0]-hepto-3-yl)ethyl]silane(EpoPS), thiocyanatopropyltriethoxysilane (TCPS), and acryloxypropyltrimethoxysilane (AcPS), which can be provided and utilized as a label, a marker, or the like for qualitative test and quantitative test for such as prophylactic agent, therapeutic agent, diagnostic agent, diagnostic and therapeutic agent or the like in dental, medical and veterinary fields regardless of fields.
